Polar Unite vs Fitbit Charge 4

Polar Unite vs Fitbit Charge 4

The Fitbit Charge 4 is a bracelet style activity tracker with built-in GPS. It is arguably the best value for money Fitbit that you can buy right now. 

The Polar Unite is essentially a dumbed-down version of the Polar Ignite. It has all of the main features that you would expect from a Polar Sports Watch, except a GPS tracker. While some people might be fine with this setup, runners and cyclists should pay attention. If you opt for the Polar Unite, you will have to take your phone with you on every ride or run that you would like to track accurately. 

Now that we’ve established a basic overview of these watches, let’s dive into the details. 

Key Similarities - Polar Unite vs Fitbit Charge 4

Polar Unite

Fitbit Charge 4

24/7 Activity Tracking

Sleep Tracking

Wrist-Based HRM

Indoor + Outdoor Running

Indoor + Outdoor Cycling

20 Activity Modes (or more)


Phone Notifications

Guided Breathing

Bluetooth Connectivity

Customizable Clock Face

V02 Max Estimates

Pool Swimming

Triathlon Capable

Key Differences - Polar Unite vs Fitbit Charge 4

Polar Unite

Fitbit Charge 4


Connect With Phone


Screen Resolution

240 x 204 pixels

160 x 100 pixels

Screen Size

1.7" (44 mm) Diameter

1.0" (25.4mm) Diameter

Screen Color

Full Color


Water Proof

30 meters

50 meters

Total Sports Modes



Guided Workouts

Built-In Altimeter

Music Control From Watch

Payments From Watch

Floors Climbed

WiFi Connectivity

Smartwatch Battery Life

Up to 4 Days

Up To 7 Days

GPS Battery Life

Up to 50 Hours

Up to 5 Hours

Explanation of Main Differences

  1. Built-In GPS: The Fitbit Charge 4 has a built-in GPS, whereas the Polar Unite does not. This is a big win for the Fitbit unit.
  2. Sports Modes – The Polar Unite support over 100 sports modes. The Fitbit Charge 4 only supports 16 sports modes.
  3. Screen Shape & Size – The Polar Unite has round 240 x 204 pixel screen. The Charge 4 has a rectangular 160 x 100 pixel screen.
  4. Battery Life – The smartwatch battery life of the Charge 4 (7 days) is almost double the smartwatch battery of the Polar Unite (4 days).
  5. Watch Style – The Polar Unite has a classical watch face design with a round face. The Fitbit Charge 4 is effectively a bracelet with activity tracking features.
  6. Optical Heart Rate Monitor – Polar’s precision prime wrist-based HRM is about as good as it gets. The Fitbit Charge 4’s heart rate monitor is okay, but not quite as accomplished as the Unite.

Polar Unite Sports Modes

Aerobics Aqua fitness Backcountry skiing Badminton
Ballet Ballroom Dancing Baseball Basketball
Beach volley Biathlon Body Mind Yoga Bootcamp
Boxing Canoeing Circuit training Classic roller skiing
Classic XC skiing Climbing Indoor Core Yoga Cricket
Cross-trainer Cycling Dancing Disc golf
Downhill skiing Disc Golf Backcountry Skiing Downhill Skiing
Field hockey Finnish baseball Fitness dancing Fitness martial arts
Floorball Football Freestyle roller skiing Freestyle XC skiing
Functional training Futsal Golf Group exercise
Gymnastics Handball High-intensity Training Hiking
Ice hockey Ice skating Indoor cycling Indoor rowing
Inline skating Jazz Jogging Judo
Kayaking Kickboxing Kitesurfing Latin dancing
Les Mills Modes Mobility (dynamic) Mobility (static) Modern dancing
Mountain biking Nordic walking Orienteering Other indoor
Other outdoor Pilates Riding Road cycling
Road running Roller skating Rowing Rugby
Running Sailing Show jumping Skating
Ski orienteering Skiing Snowboarding Snowshoe trekking
Soccer Spinning Squash Step workout
Street Dancing Strength Training Stretching Surfing
Swimming Table Tennis Telemark Skiing Tennis
Track & Field Trail Running Treadmill Running Trotting
Ultra Running Volleyball Wakeboarding Walking
Water Skiing Wheelchair Racing Windsurfing Yoga

Fitbit Charge 4 Sports Modes

Bike Bootcamp Circuit Training Elliptical
Golf Hike Interval Workout Kickboxing
Martial Arts Pilates Run Spinning
Stairclimber Swim Tennis Walk
Weights Workout Tennis Yoga

Main Reasons To Choose The Polar Unite

Main Reasons To Choose Polar Unite

100 Extra Sports Modes

This is by far the biggest advantage that the Polar Unite has over the Fitbit Charge 4. Where the Charge 4 is limited to 16 sports modes, the Polar Unite literally has more than 100. 

Ultimately, if you play lots of different sports, it’s hard to look past the value offering of the Polar Unite. In the $150 price point, you simply won’t find a watch with more sports modes to choose from (unless you choose a lower priced Polar like the M430 or M200). 

Better Optical Heart Rate Monitor

Optical heart rate monitoring is another area where Polar shines. The combination of 8 optical readers and skin contact measurement points gives the Polar Unite the best possible chance of giving you an accurate measurement from the wrist. 

Obviously optical hrm’s will never compete with a chest strap, but if you are going to rely primarily on the wrist measurements, Polar’s precision prime technology is about as good as it gets. 

Much Larger Screen

The Polar Unite has a much larger 240 x 204 pixel screen. This is considerably bigger than the 160 x 100 pixel screen found on the Fitbit Charge 4. 

Ultimately, you will find it easier to consume information displayed on the Polar Ignite screen. You should also be able to view more data fields when exercising, something runners and cyclists tend be pretty passionate about. 

Main Reasons To Choose The Fitbit Charge 4

Main Reasons To Choose Fitbit Charge 4

Built-In GPS

The Fitbit Charge 4 is the first mid-range Fitbit to introduce built-in GPS technology. This is excellent news for Fitbit fans. The lack of GPS has always been the Achilles heel of Fitbit’s product line-up, and now they are finally starting to fix that. 

The main benefit here is that you don’t need to take your phone when you go running or cycling. This makes outdoor endurance exercises infinitely more convenient.

Ironically, Polar have removed the built-in GPS from the Polar Unite, presumably to keep the costs under control (and prevent it from competing with the Polar Ignite). From our perspective, this was a regrettable decision. By removing this key element, the overall functionality and desirability of the Polar Unite has been diminished. 

The Charge 4 Has A Decent Number of Sports Modes

Admittedly the Fitbit Charge 4 can’t compete with the Polar Unite in terms of the total number of sports modes. However, it still has an adequate number of activity modes to choose from, including running, cycling, yoga, cardio and weight training. In other words, there are enough modes to cater to the needs of most casual sports people and fitness enthusiasts. 

Some People Might Prefer The Bracelet Style

The Polar Unite has a traditional watch shape which should suit most men and women. 

The Fitbit Charge 4 continues the bracelet style that the Charge line-up has become famous for. Ultimately, if you prefer the bracelet style of the Charge 4, it should be pretty easy for you to choose between these two units. 

It's The Best Value Fitbit You Can Buy

The Charge 4 might not have the high res screen of the Fitbit Versa, but the decision to include the GPS in the product means that it is technically the more accomplished sports watch. 

When you consider the relatively affordable price bracket, it’s easy to conclude that the Charge 4 is the best value for money Fitbit that you can buy right now. The price-to-value ratio is literally as good as it gets from Fitbit. 

Final Thoughts

We’ve run through all the key similarities and all the key differences between the Polar Unite and the Fitbit Charge 4. If you’re still undecided at this point, these final buying tips may help. 

Go for the Polar Unite if: 

  • You don’t mind taking your phone with you when running or cycling outdoors
  • You play loads of different sports
  • You want a better quality wrist-based heart rate monitor
  • You want access to the Polar Flow training platform (excellent training information)

Go for the Fitbit Charge 4 if: 

  • You want a built-in GPS, which makes tracking running and cycling much more convenient
  • You prefer the bracelet style design of the watch 
  • You don’t mind the smaller screen size
  • You want to control music playing on your phone using your watch (rather than the phone screen)
  • You want a good value for money fitness tracker than can track all the most popular activites (running, cycling, cardio workouts, weight training, yoga and more)